text: var roleTanker = {
  
      /** @param {Creep} creep **/
      run: function(creep) {
  	    if(creep.carry.energy < creep.carryCapacity) {
  	       var sources = creep.room.find(FIND_SOURCES);
              if(creep.harvest(sources[0]) == ERR_NOT_IN_RANGE) {
                  creep.moveTo(sources[0]);
              }
  	    }    
  	    else {
              var targets = creep.room.find(FIND_STRUCTURES, {
                      filter: (structure) => {
                          return (structure.structureType == STRUCTURE_SPAWN ||
                                  structure.structureType == STRUCTURE_EXTENSION ||
                                  structure.structureType == STRUCTURE_TOWER) && structure.energy < structure.energyCapacity;
                      }
              });
              if(targets.length > 0) {
                  if(creep.transfer(targets[0], RESOURCE_ENERGY) == ERR_NOT_IN_RANGE) {
                      creep.moveTo(targets[0]);
                  }
              }
  	    }
      }
  };
  
  
  module.exports = roleTanker;
  